1. Field of the Invention
The present invention relates to a power control system of a monitor, and more particularly, to an apparatus and a method for conserving power in a monitor by controlling the power supplied to a signal sensor.
2. Description of the Related Art
There have been efforts for reducing power consumed by electric and electronic products, to decrease the consumption of electric energy generated using the oil and atomic power and for reducing environmental pollution. Among these electric and electronic products, a display device, a peripherical device of a computer system, uses high voltage so that lots of efforts have been made to reduce its power consumption.
In general, monitors are peripheral devices connected to a computer system for displaying information input by a user or data generated in a computer on their screens. In order to reduce power consumption in such monitors, the screens of the monitors must automatically turn off when not being used.
Generally, a display device comprises control means for saving consumption power. In one approach, the control means maybe implemented by a Display Power Management System (DPMS) mode, proposed by Video Electronics Standard Association (VESA) in U.S.A.
The DPMS mode functions to manage power of a display device, which is one of the peripheral devices of a computer, according to a used state of the computer to save the power.
In conformity with the VESA, the computer selectively supplies or blocks horizontal and vertical synchronous signals to the display device according to its used state, and the display device manages power according to the presence of the horizontal and vertical synchronous signals from the computer.
The power management states are classified into an on state, a stand-by state, a suspend state and a power off state. Both the horizontal and vertical synchronous signals are applied at the on state, and only the vertical synchronous signal is applied at the stand-by state. Only the horizontal synchronous signal is applied at the suspend state, and either the horizontal or vertical synchronous signal is not applied at the power off state.
The power management state is sequentially changed to the on state stand-by state suspend state power off state with the continuous lapse of unused time of the computer. It is commonly prescribed that consumption power of the display device be about 80 W at the on state, 65 W or less at the stand-by state, 25 W or less at the suspend state and 5 W or less at the power off state.